In a large bowl whisk together 2 cups of the flour, corn starch, flax, instant yeast, sugar, salt. Using a sturdy spoon mix in the milk, vanilla, and soft butter. Mix well until no dry ingredients can be seen. Mix in 1/2 cup flour and add more flour as necessary to get a dough that you can pinch and it doesn't stick to your fingers but still feels soft.
Turn the dough onto a lightly floured counter or cutting board. Knead for 2 minutes until the dough is smooth looking. You don't need to knead the dough for long.
Place the dough into a lightly oiled bowl, cover, and let rest for one hour. The dough should double in size.
Preheat oven to 375°F. Line a baking sheet with parchment paper. Set aside.
In a small bowl whisk together the sugar and cinnamon for the filling. Measure out the milk and set aside. Don't mix the milk with the cinnamon sugar.
Divide the dough into four equal pieces. On an unfloured surface, lightly roll the pieces into rounds. Don't compress or squish them. Just roll them a little to make them round.
Roll one dough ball into a 10" disc. It should be fairly thin but be careful to not rip or tear the dough. Place the rolled piece onto the parchment lined baking sheet. Brush a little milk onto the dough, leaving 1/4" edge, and then sprinkle 1/3 of the cinnamon sugar onto the dough. Again, leaving a 1/4" edge.
Roll out the second piece of dough into a 10" disc. Place onto the first layer, gently press to remove any air pockets. Brush with milk, sprinkle on sugar, and repeat for the third piece. Roll out the final dough ball and place on top. Gently press down to remove air pockets and to get the edges to stick together.
Use the bottom of a drinking glass, about 2" diameter, to gently make an impression in the center of your dough. Remove the glass. Using a sharp knife, cut the dough straight down up to the impression in the center. Start with making four cuts in the dough so that it's divided into quarters, then divide the quarters so you have eight cuts, then divide the eight so you have 16 total cuts.
Hold two of the pieces and twist them in opposite directions three times. Pinch the end together. Repeat until you have 8 points on your snowflake bread!
Cover loosely with plastic wrap and let rise for 30 minutes. Brush the exposed dough, not the cinnamon layers, with a little milk then bake for 25 minutes. Let cool for 10-15 minutes before serving. Enjoy!